I have been saying for ages that the only thing that matters in a tablet is the available content: What can I download to the device, and watch on a plane, train, automobuggie? Everything can stream Netflix, surf the web, etc. The number of downloadable TV shows and movies is by far the most meaningful difference between tablets.

The assumption: iTunes and Amazon offer so much more content, the other services - and thus, tablets that aren't iPads or Kindles - are pointless.

Is that assumption correct? Or more to the point, how can you tell?

There is no list that tells you what shows are available and where. My assumption about content is based on trying to find shows while reviewing various tablets over the past year. In my mind, if a show/movie is available, it's going to be on iTunes and/or Amazon. They're by far the largest, oldest, and best established services. Upstarts like Google Play and others don't have - or don't seem to have - the ability to get deals with the content providers. No deals? No content.

So the real question is one of methodology. How does one get an accurate enough sample of available content to truly make a judgment? It's fair to say there are millions of TV seasons and movies potentially to choose from. Even if I spend ages checking 1,000 of them, that's a paltry sample size. Without a reasonable sample, any result is highly suspect.

The lazy way to do this would be to pick a handful of shows I like, and judge from that. There is some reasonableness to this. In theory, my favorites are random and therefore sort of constitute a random sample. But what if I only like niche programming? Or what if one service has a lot of one genre, and less of another. If I hit right on that genre. . . well, you get the point.

So what I felt was needed was a mix of what I watch, and what you watch. Well, not "you" you, but the royal "you." A "y'all," if you will. I compiled a list of the top 10 current TV shows, the top 10 TV shows of all time, and the top 20 movies. In some cases, popular titles weren't available on any platform, In those cases I omitted the given title and moved on to the next entry on the list. In a few cases, shows or movies were available on all the platforms, and I excluded them to save space. While this would affect a strictly numerical result, in my mind this is a pass/fail contest. Either you have the most content, or you're irrelevant. In other words, missing titles are vastly more significant than available, for this test.

In addition, I added 10 shows I watch, to make sure the services aren't just skimming off the popular top.

Check out the chart, and we'll discuss the results after. (UPDATE! Check out the latest version of this chart here)

(Notes: There were 50 potential titles. Amazon didn't receive a point for Star Trek:TNG, as it's streaming only with a Prime subscription, there's no download option (which is the point of this survey). For Google Play I gave a half point per title for Farscape and Battlestar for only having the show's movies available. Likewise I gave Media Hub half a point per title for not having every season/show of Law & Order and SNL. Sony gets half a point for only one season of ER, but gets a nerd-bonus half point for having the extended editions of Lord of the Rings. Yes, Media Hub did too, but it didn't have Return of the King at all, so. . .)

Even I was surprised that out of 50 potential titles, iTunes and Amazon both had 47. What's interesting is that a different 3 was missing from each. The immediate conclusion is the iPad is the winner, as it currently has access to Amazon's library in addition to Apple's own, meaning it can download all available content (as far as we can tell). The Kindle Fire is a close second.

In fairness, Sony tablets will have access to Unlimited and Google Play, while Samsung tablets will have access to Media Hub and Google Play. So both tablet's totals should incorporate the (relatively few) titles available on Play and not on their "native" services (or, in Samsung's case, vice versa).

So in this case Sony tablets have a 41/50 (39+Play) advantage over other Android tablets, while Samsung has a 23/50 (10+Play) edge over other Android tablets (see notes above for half-point explanations).

As you can see, even with access to two media services, Samsung and Sony still leave out a lot of stuff. There isn't a case, at least with this data, where Sony, Google, or Media Hub, offer something you can't find on Amazon or iTunes, so wider availability of these services from a content accessibility standpoint isn't a big deal.

There were two surprises, to me at least. The first is how decent Sony's Unlimited service is. I said as much in my initial review, but having roughly 80% of the content of Amazon/iTunes is respectable. Respectable, at least, when you compare it to the abysmal Google Play and Media Hub. I'll stop picking on Media Hub, because as yet Samsung hasn't really positioned it as a competitor to these other services - it's more like a value-add. Besides, Samsung's tablet division is having enough problems right now.

So let's look at Google Play. Or rather, let's not. That's the second surprise. I had assumed even with a cursory glance it wasn't as good as Amazon/iTunes, but I had no idea it would be this bad. Less than half the content of the real services? That's embarrassing. The problem is obvious: television. There are effectively no TV shows available. Even if you ignore that ridiculous shortcoming, there are still only 75% of the movies. So the Nexus 7 is supposed to be as good as the Kindle Fire. . .why?

A few final notes on this exercise. Sony Unlimited's search functionality is horrid. Search for a show, and it displays all the episodes for that show, with no obvious way to sort by series or season. For shows with a lot of seasons (like Top Gear) it makes finding individual episodes tedious. You can, alternatively, go to the "TV shows" section where there's an alphabetical listing of every show available. Find your show this way and it lists seasons, but why not in the search function? Bass ackwards if you ask me.

Remember, of course - licensing deals are not forever, and change on a regular basis. So this is the state of the tablet world now and for the near future only. If anything major changes, I'll update our chart.

Lastly, I find it ironic that the only TV show available from every provider was Friday Night Lights, given how few people ever actually watched it.

So once again, the iPad is the only tablet worth buying, unless you want something cheaper or smaller, in which case, get the not-a-tablet Kindle Fire.